JP2019536627A - Ammoxidation catalyst with selective by-product HCN production - Google Patents

Abstract

A catalyst composition and method useful for the conversion of an olefin selected from the group consisting of propylene, isobutylene or mixtures thereof to acrylonitrile, methacrylonitrile, hydrogen cyanide and acetonitrile and mixtures thereof, wherein the catalyst comprises: Provided are catalyst compositions and methods that exhibit increased selectivity for hydrogen cyanide as compared to prior art catalysts.

Description

  The present invention is an improved catalyst for use in the ammoxidation of unsaturated hydrocarbons to the corresponding unsaturated nitriles, comprising hydrogen cyanide (HCN) by-products without significant reduction in the yield of unsaturated nitriles. Catalysts that unexpectedly provide increased yield of co-product. In particular, the present invention provides an improved catalyst composition for the ammoxidation of propylene and / or isobutylene to acrylonitrile and / or methacrylonitrile, respectively, and hydrogen cyanide (HCN) and acetonitrile by-product, The catalyst exhibits increased selectivity for hydrogen cyanide as compared to prior art catalysts, wherein the catalyst comprises a complex of bismuth, molybdenum, iron, cerium and a metal oxide comprising other promoter elements, wherein the catalyst comprises The present invention is directed to a catalyst composition characterized by the ratio of iron to bismuth and cerium contained in the catalyst.

Catalysts containing oxides of iron, bismuth and molybdenum promoted by appropriate elements are used to produce acrylonitrile and / or methacrylonitrile at elevated temperatures, with ammonia and oxygen (usually in the form of air). In the presence, it has been used for many years for the conversion of propylene and / or isobutylene. In particular, British Patent No. 1,436,475; US Patent No. 4,766,232; US Patent No. 4,377,534; US Patent No. 4,040,978; US Patent No. 4,168,246; No. 4,469,891 are directed to bismuth-molybdenum-iron catalysts which can be promoted with Group II elements to produce acrylonitrile. In addition, U.S. Patent Nos. 5,093,299, 5,212,137, 5,658,842, 5,834,394 and Chinese Patent CN103418400 provide high yields to acrylonitrile. For the catalysts promoted with bismuth-molybdenum shown.
In part, the present invention relates to a cerium-promoted bismuth-molybdenum-iron catalyst containing a cerium-bismuth-molybdenum phase having a greater amount of scheelite crystal structure than the earlier generation of a compositionally similar catalyst. . Such catalysts are disclosed in U.S. Patent Nos. 8,153,546; 8,258,073; 8,350,075; 8,420,566; 8,455,388. Nos. 9,211,572; 9,358,528 and U.S. Patent Publication No. 2016/0175817.
In part, the present invention relates to a promoted bismuth-molybdenum-iron ammoxidation catalyst that provides enhanced hydrogen cyanide production. U.S. Pat. No. 5,840,648 teaches a promoted bismuth-molybdenum-iron ammoxidation catalyst that incorporates calcium to provide increased hydrogen cyanide production without significant reduction in acrylonitrile production. U.S. Pat. No. 7,576,232 discloses the addition of various molybdate compounds to ammoxidation catalysts to increase the yield of hydrogen cyanide and to modify the catalytic performance of inhibiting molybdenum loss from such ammoxidation catalysts. Teach.

  The present invention is directed to improved methods and catalysts for the ammoxidation of propylene to acrylonitrile, hydrogen cyanide and acetonitrile. The methods and catalysts are characterized by a greater overall conversion of propylene to hydrogen cyanide and a greater overall conversion of propylene to acrylonitrile, hydrogen cyanide and acetonitrile than previously achieved with other methods and catalysts. Historically, catalysts that provided an increase in hydrogen cyanide yield provided an increase in hydrogen cyanide yield with a corresponding decrease in acrylonitrile yield. The catalyst of the present invention does not meet this historical trend. The methods and catalysts of the present invention provide increased hydrogen cyanide production without a significant decrease in acrylonitrile production, and an overall increase in acrylonitrile, hydrogen cyanide and acetonitrile production.

In one embodiment, the present invention provides a catalyst composition comprising a composite of a metal oxide,
The relative ratios of the listed elements in the catalyst are represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Cr n Q q O x
Wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium;
D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium;
E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium At least one element selected from the group consisting of:
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one of samarium, praseodymium and neodymium, and a, b, c, d, e, f, g, h, n, m and x are each “m” molybdenum (Mo) The atomic ratio of bismuth (Bi), iron (Fe), A, D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O) to the atoms of
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is from 0 to 5,
d is 0.1 to 12,
e is 0-5,
f is 0 to 5,
g is 0 to 0.2;
h is 0.01 to 5,
m is 10 to 15,
n is 0 to 5,
q is from 0 to 2.476, and x is the number of oxygen atoms required to satisfy the valency requirements of the other component elements present;
0.4 <b / (a + h) and 0.3 ≦ (a + h) / d)).

In another embodiment of the above composition, independently
0.3 ≦ (a + h) / d ≦ 1,
0.8 ≦ h / b ≦ 5,
0.5 ≦ a / h <1.5,
0.45 ≦ (a + h) / d ≦ 1,
0 ≦ q / (a + h + q) <0.16, and / or 0 ≦ m− (3a + 2b + c + 2d + 3h + 3n) /2≦1.0
It is.

The present invention also relates to a propylene ammoxidation catalyst formulation capable of providing a yield of useful nitrile products, including a variable and reversible range of acrylonitrile and HCN. This variation in yield can be beneficial during operation of the catalyst by appropriate addition of certain catalyst additives. In particular, the yield of hydrogen cyanide is given by the formula:
A ₂ Mo _z O _{4 + 3 (z-1)}
Wherein A is Rb, Li, Na, K, Cs or a mixture thereof;
z is from 1 to about 8), compared to the amount of acrylonitrile and methacrylonitrile produced in the process by the addition of at least one molybdate compound represented by Alkali molybdate may be used with or without a support.

Further, when molybdate is added to the catalyst for the purpose of increasing hydrogen cyanide production, this trend is due to MoO ₃ , ammonium molybdate, ammonium heptamolybdate, ammonium dimolybdate and mixtures thereof in the catalyst. It can be reversed by the addition of a molybdenum oxide compound selected from the group and an alkali molybdate mixture which catalyzes the ammoxidation process. Thus, the addition of molybdenum oxide to the catalyst and alkali molybdate mixture increases the yield of acrylonitrile and methacrylonitrile compared to the amount of hydrogen cyanide produced in the process (ie, the acrylonitrile and methacrylonitrile produced). The amounts of lonitrile as well as hydrogen cyanide will reach or restore their premolybdate loading levels).

  The present invention is directed to improved mixed metal oxide catalysts and methods for ammoxidation of propylene and / or isobutylene. In particular, the present invention is an improved catalyst composition for the ammoxidation of propylene and / or isobutylene to acrylonitrile and / or methacrylonitrile and hydrogen cyanide (HCN) and acetonitrile by-products, respectively, The catalyst exhibits increased selectivity for hydrogen cyanide as compared to prior art catalysts, wherein the catalyst comprises a complex of a metal oxide including bismuth, molybdenum, iron, cerium and other promoter elements; The present invention is directed to a catalyst composition wherein the catalyst is characterized by the ratio of iron to bismuth and cerium contained in the catalyst. As used herein, "catalyst composition" and "catalyst" are synonymous and are used interchangeably.

catalyst:
In part, the present invention is a multi-component mixed metal oxide ammoxidation catalyst composition comprising a catalyst oxide composite,
The elements and the relative ratios of the elements in the catalyst composition are represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Cr n Q q O x
Wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium;
D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium;
E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium At least one element selected from the group consisting of:
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one element of samarium, praseodymium and neodymium, and a, b, c, d, e, f, g, h, n, m and x are each “m” molybdenum (Mo) Atomic ratio of bismuth (Bi), iron (Fe), A, D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O) to the atom of
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is from 0 to 5,
d is 0.1 to 12,
e is 0-5,
f is 0 to 5,
g is 0 to 0.2;
h is 0.01 to 5,
m is 10 to 15,
n is 0 to 5,
q is 0 to 2.476;
x is the number of oxygen atoms required to satisfy the valency requirements of the other constituent elements present;
0.4 <b / (a + h) and 0.3 ≦ (a + h) / d9).

In one embodiment, A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium. In one embodiment, the catalyst composition does not include potassium.
In one embodiment, D is at least an element selected from the group consisting of nickel, cobalt and magnesium. In one embodiment, D is nickel.

  In one embodiment, the catalyst does not contain tellurium, antimony or selenium. In another embodiment, the component or element designated by "E" in the above formula may include tellurium and / or antimony. In another embodiment, the component or element designated by "E" in the above formula is at least one element selected from the group consisting of chromium, aluminum, gallium, indium, arsenic, antimony, and tellurium. In another embodiment, “e” is zero (ie, the composition described above does not contain the component or element designated by “E” in the formula above). In one embodiment, h is 0.01-5. In one embodiment, "F" may further include lead (Pb). In another embodiment, "F" does not include lead (Pb). In one embodiment, “m” is twelve.

In part, the catalyst composition is b / (a + h) (where "b" is the relative amount of iron in the catalyst, "a" is the relative amount of bismuth in the catalyst, and "h" Is the relative amount of cerium). In one embodiment, 0.4 <b / (a + h). In another independent embodiment, 0.45 ≦ b / (a + h).
In part, the catalyst composition comprises (a + h) / d (, where “a” is the relative amount of bismuth in the catalyst, “h” is the relative amount of cerium in the catalyst, and “d” Is the relative amount of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium in the catalyst). These relative amounts are subscripts of the elements in the catalyst formula or, in the case of "d", any nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium present in the catalyst. And the sum of the subscripts obtained from the catalytic formula for barium. In one embodiment, 0.3 ≦ (a + h) / d. In another independent embodiment, 0.15 ≦ (a + h) / d. Other independent embodiments are (each column below is an embodiment):
0.15 ≦ (a + h) / d ≦ 1,
0.3 ≦ (a + h) / d ≦ 1,
0.3 ≦ (a + h) /d≦0.8,
0.3 ≦ (a + h) /d≦0.6,
0.3 ≦ (a + h) /d≦0.4,
(A + h) / d ≦ 1,
(A + h) /d≦0.8,
(A + h) /d≦0.6,
(A + h) /d≦0.5 and (a + h) /d≦0.4.

  The catalyst composition has a value of "m-[(3a + 2b + c + 2d + 3h + 3n) / 2]" ("m" is the relative amount of molybdenum in the catalyst, "a" is the relative amount of bismuth in the catalyst, and "b" Is the relative amount of iron in the catalyst, “c” is the relative amount of the “A” element (ie, lithium, sodium, potassium, rubidium and cesium) in the catalyst, and “d” is the relative amount of iron in the catalyst. Are the relative amounts of the "D" elements (i.e., nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, calcium, and barium), and "h" is the relative amount of cerium in the catalyst; Is the relative amount of chromium in the catalyst.). These relative amounts are subscripts of the elements in the catalyst formula or, in the case of "a", derived from the catalyst formula for any lithium, sodium, potassium, rubidium and cesium present in the catalyst. The subscript obtained from the catalytic formula for any nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium present in the catalyst. This is the sum of the characters. In one embodiment, 0 ≦ [m − [(3a + 2b + c + 2d + 3h + 3n) / 2]] ≦ 1.0.

In one embodiment, "Q" is samarium. In other embodiments, the catalyst does not include a “Q” element (ie, “q” is zero). In other embodiments, "q" is greater than zero. In another embodiment, "q" is 0-2.476.

The catalyst composition is q / (a + h + q) (“q” is the relative amount of samarium, praseodymium and neodymium in the catalyst, “a” is the relative amount of bismuth in the catalyst, and “h” is The relative amount of cerium in the catalyst). These relative amounts are the subscripts of the elements in the catalyst formula or, in the case of "q", the subscripts obtained from the catalyst formula for any samarium, praseodymium and neodymium present in the catalyst. Is the sum of In one embodiment, 0 ≦ q / (a + h + q) and q / (a + h + q) <0.16. In another embodiment, 0 ≦ q / (a + h + q) and q / (a + h + q) <0.05. In another embodiment, 0.01 <q / (a + h + q) and q / (a + h + q) <0.12. Other independent embodiments are (each column below is an embodiment):
0 ≦ q / (a + h + q),
0.01 <q / (a + h + q),
0.02 <q / (a + h + q),
0.03 <q / (a + h + q),
0.04 <q / (a + h + q),
q / (a + h + q) <0.16,
q / (a + h + q) <0.14,
q / (a + h + q) <0.12,
q / (a + h + q) <0.10,
q / (a + h + q) <0.08,
q / (a + h + q) <0.06 and q / (a + h + q) <0.05.

The catalyst composition may be characterized by a relationship of h / b ("h" is the relative amount of cerium in the catalyst and "b" is the relative amount of iron in the catalyst). These relative amounts are subscripts of the elements in the catalytic formula. In one embodiment, 0.8 ≦ h / b ≦ 5. Other independent embodiments are (each column below is an embodiment):
1.2 ≦ h / b ≦ 5,
1.5 ≦ h / b ≦ 5,
1.2 ≦ h / b,
1.5 ≦ h / b,
0.8 ≦ h / b and h / b ≦ 5.
It is noted that catalysts described within the range described by 0.8 ≦ h / b ≦ 5 tend to be more potent in that they exhibit lower friction loss as measured by a submerged jet rub test. It was found.

The catalyst composition may be characterized by the relationship (a / h), where "a" is the relative amount of bismuth in the catalyst and "h" is the relative amount of cerium in the catalyst. . These relative amounts are subscripts of the elements in the catalytic formula. In one embodiment, 0 <a / h ≦ 1.5. Other independent embodiments are (each column below is an embodiment):
0.2 ≦ a / h ≦ 1.5,
0.3 ≦ a / h ≦ 1.5,
0.4 ≦ a / h ≦ 1.5,
0.45 ≦ a / h ≦ 1.5,
0.5 ≦ a / h ≦ 1.5,
0.2 ≦ a / h,
0.3 ≦ a / h,
0.4 ≦ a / h,
0.45 ≦ a / h,
0.65 ≦ a / h,
0.5 ≦ a / h,
0.7 ≦ a / h,
0.8 ≦ a / h,
0.90 ≦ a / h,
a / h ≦ 1.2 and a / h ≦ 1.5.

In an alternative embodiment of the catalyst of the present invention, the present invention provides a catalyst composition comprising a composite of a metal oxide, wherein the relative ratio of the listed elements in said catalyst is represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Ni i Co j Mn k Mg l Q q O x
Wherein A is at least one element selected from the group consisting of sodium, potassium, rubidium and cesium; and D is at least one element selected from the group consisting of zinc, calcium, strontium, cadmium and barium. Two elements;
E is at least one element selected from the group consisting of chromium, tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, germanium and about At least one element selected from the group consisting of less than 10 ppm lead;
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one of samarium, praseodymium and neodymium;
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is 0.01 to 5,
d is 0 to 12,
e is 0-5,
f is 0 to 5,
g is 0 to 0.2;
h is 0.01 to 5,
i is 0.1 to 12,
j is 0 to 12,
k is 0 to 12,
l is from 0 to 12,
m is 10 to 15,
q is 0 to 2.476;
x is the number of oxygen atoms required to satisfy the valency requirements of the other constituent elements present;
0.4 <b / (a + h),
A catalyst composition represented by 0.2 <i / (i + j + k + 1), and z = d + i + j + k + 1 and 0.3 ≦ (a + h) / z.

  The catalyst of the present invention may be used either supported or unsupported (ie, the catalyst may include a support). Suitable supports are silica, alumina, zirconium, titania or mixtures thereof. Typically, the support acts as a binder for the catalyst, yielding a stronger (ie, more friction resistant) catalyst. However, for commercial applications, a suitable blend of both the active phase (ie, a composite of the above-described catalyst oxide) and the support is essential to obtain catalytically acceptable activity and hardness (friction resistance). . Typically, the support comprises between 40 and 60 weight percent of the supported catalyst. In one embodiment of the present invention, the support may include as little as about 30 weight percent of the supported catalyst. In another embodiment of the present invention, the support may include as much as about 70 weight percent of the supported catalyst.

  In one embodiment, the catalyst is supported using a silica sol. Typically, the silica sol contains some sodium. In one embodiment, the silica sol contains less than 600 ppm sodium. In another embodiment, the silica sol contains less than 200 ppm sodium. Typically, the average colloidal particle diameter of the silica sol is between about 15 nm to about 50 nm. In one embodiment of the present invention, the average colloidal particle diameter of the silica sol is about 10 nm and can be as low as about 4 nm. In another embodiment of the present invention, the average colloidal particle diameter of the silica sol is about 100 nm. In another embodiment of the present invention, the average colloidal particle diameter of the silica sol is about 20 nm. In another embodiment of the present invention, the average colloidal particle diameter of the silica sol is about 40 nm.

Nitrogen Utilization The present invention relates to the relative yield of acrylonitrile, acetonitrile and hydrogen cyanide produced in the process, and / or
α = [(% AN + (3 ×% HCN) + (1.5 ×% ACN)) ÷% PC] × 100
Wherein% AN is the acrylonitrile yield and% AN ≧ 82;
% HCN is hydrogen cyanide yield and% HCN ≧ 5;
% ACN is the acetonitrile yield,
% PC is the propylene conversion,
α is greater than 102.5) and a process for the production of acrylonitrile, acetonitrile and hydrogen cyanide, characterized by the catalyst defined by

In another embodiment, independently,% AN is greater than or equal to 82.5;% PC is greater than 90;% PC is greater than 95;% PC is greater than 98; Greater than. As used herein, "acrylonitrile yield" means the mole percent yield of acrylonitrile calculated as follows (expressed as a number without any percent signs):
(Moles of acrylonitrile produced / moles of propylene fed to the reactor) x 100. "Hydrogen cyanide yield" means the molar percent yield of hydrogen cyanide calculated as follows (expressed as a number without any percent signs): [(moles of hydrogen cyanide produced {3)} Moles of propylene supplied] × 100. "Acetonitrile yield" means the mole percent yield of acetonitrile calculated as follows (expressed as a number without any percent signs): [(moles of acetonitrile formed {1.5)} reactions Mol of propylene supplied to the vessel] × 100. Propylene conversion means the mole percent conversion of propylene to product and by-products, calculated as follows (expressed as a number without any percent sign): [(moles of propylene exiting the reactor Minus the moles of propylene fed to the reactor) {moles of propylene fed to the reactor] x 100.
“Α” is a measure of “nitrogen insertion” or “nitrogen utilization” (ie, the nitrogen obtained from ammonia during an ammoxidation reaction is combined with propylene to form a compound having a functional group “—CN” As such, the larger the “α”, the greater the overall conversion of propylene to acrylonitrile, hydrogen cyanide and acetonitrile). The catalyst of the present invention is characterized by a high "α" (ie, greater than 102.5), which is how efficient the catalyst is at utilizing ammonia for the ammoxidation of propylene to acrylonitrile. That is the standard.

Catalyst preparation:
The catalyst may be prepared by any of numerous methods of catalyst preparation known to those skilled in the art. A typical method of preparation begins with the formation of a mixture of water, a source compound of molybdenum and a support material (eg, silica sol). Alone, the source compounds of the remaining elements in the catalyst combine with water to form a second mixture. Thereafter, the two mixtures are stirred together at a slightly elevated temperature (approximately 65 ° C.) to form a catalyst precursor slurry. Thereafter, the catalyst precursor slurry is dried, denitrified, and then calcined as described below.
In one embodiment, the elements in the catalyst composition identified above are combined with an aqueous catalyst precursor slurry, and the resulting aqueous precursor slurry is dried to form a catalyst precursor. Once formed, the catalyst precursor is calcined to form the catalyst. However, unique to the method of the present invention are:
(I) In an aqueous solution, combine the Bi and Ce source compounds and optionally Li, Na, K, Rb, Cs, Ca, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, Combining one or more of erbium, thulium, ytterbium, lutetium, scandium, yttrium, Pb and W to form a mixture (ie, a first mixture);
(Ii) adding a source compound of molybdenum to the mixture (ie, the first mixture) and reacting with the mixture to form a precipitate slurry; and (iii) separating the precipitate slurry from the remaining catalyst in the catalyst. Combining the elemental and remaining molybdenum source compounds to form an aqueous catalyst precursor slurry.

As used herein, a "source compound" is a compound that contains and / or provides one or more metals for a mixed metal oxide catalyst composition. As used herein, “remaining elements” or “remaining elements in the catalyst” are “A”, “D”, “E” in the above formulas that were not included in the first mixture. , "F" and "G" and the amounts of those elements. In one embodiment, some elements may be part of both the first and second mixtures. Further, as used herein, "residual molybdenum" or "residual molybdenum in the catalyst" was not present in the precipitate slurry (ie, was not included in the preparation of). Refers to the amount of molybdenum required in the catalyst. Finally, the sum of the amounts of molybdenum provided in the molybdenum source compound added to (ii) and (iii) is equal to the total amount of molybdenum present in the catalyst.

In the above catalyst preparation, the remaining elemental and residual molybdenum source compounds combined with the precipitate slurry may be combined in any order of such residual elements and residual molybdenum, or even a combination thereof. Good. In one embodiment, a mixture of the remaining elements and the remaining molybdenum source compound is combined with the precipitate slurry to form an aqueous catalyst precursor slurry. In another embodiment, the mixture of (i) the source compound of the remaining elements is combined with the precipitate slurry, and (ii) the remaining molybdenum source compound is separately added to the precipitate slurry to form an aqueous catalyst. Form a precursor slurry. In another embodiment, the remaining elemental and molybdenum source compounds are added individually (ie, one at a time) to the precipitate slurry. In another embodiment, a plurality (ie, more than one) mixture of the remaining elements and the remaining molybdenum source compound, wherein each mixture is one or more of the remaining elements or the remaining molybdenum. A mixture containing multiple source compounds is separately added to the precipitate slurry (ie, one mixture at a time, or multiple mixtures are added simultaneously) to form an aqueous catalyst precursor slurry. . In yet another embodiment, a mixture of the source compounds of the remaining elements is combined with a source compound of molybdenum, and the resulting mixture is then added to the precipitate slurry to form a catalyst precursor slurry. In yet another embodiment, the support is silica (SiO ₂ ) and the silica is combined with the source compound for the remaining molybdenum (ie, silica) before combining the remaining molybdenum with the precipitate slurry. And the source compounds for the remaining molybdenum are combined to form a mixture, which is then individually added to the sediment slurry or combined with one or more source compounds of the remaining elements Added).

In the above catalyst preparation, molybdenum is added both in the preparation of the precipitate slurry and in the preparation of the aqueous catalyst precursor slurry. At the atomic level, the minimum amount of molybdenum added to form a precipitate slurry is determined by the following relationship:
Mo = 1.5 (Bi + Ce) +0.5 (Rb + Li + Na + K + Cs) + (Ca) +1.5 (lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and Total number of yttrium atoms) + (Pb)-(W)
Here, in the above relation, “Mo” is the number of molybdenum atoms added to the first mixture, and is “Bi”, “Ce”, “Rb”, “Li”, “Na”, “ "K", "Cs", "Ca", "Pb" and "W" are the values of bismuth, cerium, rubidium, lithium, sodium, potassium, cesium, calcium, lead and tungsten, respectively, present in the first mixture. The number of atoms.

In the above catalyst preparation, typically, the amount of molybdenum added to the first mixture to form a precipitate slurry is about 20-35% of the total molybdenum in the final catalyst. In one embodiment, the source compound for the remaining molybdenum present in the catalyst is the source compound of the remaining elements prior to combining the mixture of the remaining elements with the precipitate slurry to form a catalyst precursor slurry. Added to the mixture (ie, the second mixture). In another embodiment, the molybdenum source compound containing the remaining molybdenum present in the catalyst is mixed with the remaining elemental source compound mixture (ie, the second mixture) to form a catalyst precursor slurry. ) Is added to the precipitate slurry either before, after or simultaneously.
In the above preparation, the source compounds of Bi and Ce, and optionally one or more of Li, Na, K, Rb, Cs, Ca, rare earth elements, Pb and W, are combined in an aqueous solution to form a mixture To form In one embodiment, bismuth nitride and optionally other metal nitrides (i.e., nitrides of Li, Na, K, Rb, Cs, Ca, rare earth elements and / or Pb) are dissolved in an aqueous solution of cerium ammonium nitrate. Is done. If tungsten is added, the source compounds are typically, ammonium paratungstate, a _{6 (NH 4) 10 H 2} (W 2 O 7). As used herein, "rare earth element" refers to at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, scandium and yttrium. Means

Added to the mixture comprising bismuth and cerium (and optionally one or more of Li, Na, K, Rb, Cs, Ca, rare earth elements, Pb and / or W) is a source compound of molybdenum It is. In one embodiment, the source compound of molybdenum is ammonium heptamolybdate dissolved in water. Upon addition of the molybdenum source compound to the mixture comprising bismuth and cerium, the reaction takes place, causing a precipitate, and the resulting mixture is a precipitate slurry.
The precipitate slurry is then combined with a mixture of the source compound of the remaining elements of the catalyst and the source compound of molybdenum to form an aqueous catalyst precursor slurry. The mixture of the source compound of the remaining element and the source compound of molybdenum may be combined with the source compound of the remaining element in the aqueous solution (e.g., combining the source compound in water) and then combining the source compound of molybdenum. It may be prepared by adding. In one embodiment, the source compound of molybdenum is ammonium heptamolybdate dissolved in water. When combining the sediment slurry with the remaining element / molybdenum mixture, the order of addition is not important, ie, the sediment slurry may be added to the remaining element / molybdenum mixture, or the remaining element / molybdenum mixture May be added to the precipitate slurry. The aqueous catalyst precursor slurry is maintained at an elevated temperature.

The amount of aqueous solvent in each of the aqueous mixtures and slurries described above may vary due to the solubility of the source compounds that are tailored to form the particular mixed metal oxide. The amount of aqueous solvent should be at least sufficient to obtain a slurry or a mixture of solids and liquid that can be stirred.
In each case, the source compounds are preferably combined and / or reacted according to a protocol that involves mixing the source compounds during the combination and / or reaction steps. The particular mixing mechanism is not critical and can include, for example, mixing (eg, stirring or agitating) the components during the reaction by any effective method. Such methods include, for example, shaking, rotating, or vibrating the container containing the components, for example, to stir the contents of the container. As such a method, for example, a driving force for supplying a relative movement between the stirring member and the reaction vessel, which is connected to the stirring member at least partially disposed in the reaction vessel, or connected to the reaction vessel, is used. Stirring by use is also mentioned. The stirring member may be a shaft-driven and / or shaft-supported stirring member. The driving force can be connected directly to the stirring member or indirectly to the stirring member (eg, via electromagnetic coupling). Mixing is sufficient to mix the components to allow an efficient reaction between the components of the reaction medium, forming a more homogeneous reaction medium as compared to the unmixed reaction (eg, a more homogeneous reaction medium). To produce a mixed metal oxide precursor). This results in more efficient consumption of starting materials and a more homogeneous mixed metal oxide product. Mixing the precipitate slurry during the reaction step also causes the precipitate to form in solution rather than on the sides of the reaction vessel. Even more advantageously, forming a precipitate in solution allows for particle growth over the surface of the particles rather than a limited exposed surface when growth occurs outside the reaction vessel walls.

Molybdenum source compounds can include molybdenum (VI) oxide (MoO ₃ ), ammonium heptamolybdate or molybdate. The source compound of molybdenum can be introduced from any molybdenum oxide such as dioxide, trioxide, pentoxide or heptaoxide. However, it is preferred that a hydrolyzable or degradable molybdenum salt is utilized as the source compound for molybdenum.
Typical source compounds for the catalyst bismuth, cerium and the remaining elements are metal nitrides. Such nitride salts are readily available and readily soluble. Bismuth source compounds can include oxides or salts that will yield oxides upon calcination. A water-soluble salt which is easily dispersed by heat treatment but forms a stable oxide is preferable. In one embodiment, the source compound of bismuth, bismuth nitride, Bi (NO ₃₎ is ₃ · 5H ₂ O.

The cerium source compound may include an oxide or salt that will yield an oxide upon calcination. A water-soluble salt which is easily dispersed by heat treatment but forms a stable oxide is preferable. In one embodiment, the cerium source compound is cerium ammonium nitrate, (NH ₄ ) ₂ Ce (NO ₃ ) ₆ . In another embodiment, the source compound of cerium, cerium nitride, Ce (NO ₃₎ is ₃ · 6H ₂ O.
The iron source compound may be obtained from any compound of iron that will produce an oxide upon calcination. When using other elements, water-soluble salts are preferred because of the ease with which they can be uniformly dispersed in the catalyst. Most preferred is ferric nitride.

Source compounds for the remaining elements can be derived from any suitable source. For example, cobalt, nickel and magnesium can be introduced into the catalyst using a nitride salt. Further, magnesium can be introduced into the catalyst by heat treatment as insoluble carbonates or hydroxides that form oxides. Phosphorus can be introduced into the catalyst as an alkali metal salt or alkali rare earth metal salt or ammonium salt, but is preferably introduced as phosphoric acid.
The source compound for the alkaline component of the catalyst may be introduced to the catalyst as an oxide, which will yield the oxide upon calcination, or as a salt.
In addition to water, solvents may be used to prepare mixed metal oxides according to the invention, such as, but not limited to, methanol, ethanol, propanol, diols (eg, ethylene glycol, propylene glycol, etc.). Organic acids such as alcohols, acetic acid, and other polar solvents known in the art. The metal source compound is at least partially soluble in the solvent.
As noted above, the catalysts of the present invention may be used either supported or unsupported (ie, the catalyst may include a support). Suitable supports are silica, alumina, zirconia, titania or mixtures thereof. The support may be added at any time before the catalyst precursor slurry is dried. The support may be added at any time during or after the preparation of any mixture of elements, precipitate slurry or catalyst precursor slurry. Further, the support need not be added at a single point or at a stage (ie, the support may be added at multiple points in the preparation). In one embodiment, the support is combined with other components during preparation of the aqueous catalyst precursor slurry. In one embodiment, the support is added to the precipitate slurry (ie, after the precipitate slurry has been prepared). In one embodiment, the support is combined with the molybdenum source compound prior to combining the molybdenum source compound with the remaining element source compound in the catalyst, and the "second mixture" shown above. To form

  The catalyst precursor slurry is dried and denitrified (ie, removal of nitrides) to obtain a catalyst precursor. In one embodiment, the catalyst precursor slurry is dried to form catalyst particles. In one embodiment, the catalyst precursor slurry is spray dried into fine spherical catalyst particles. In one embodiment, the spray dryer outlet temperature is between 110C and 350C, preferably between 110C and 250C, most preferably between 110C and 180C. In one embodiment, the spray dryer is a co-current spray dryer (ie, the particles are sprayed co-current to the gas flow). In another embodiment, the spray dryer is countercurrent (ie, the particles are sprayed countercurrent to the gas flow). In another embodiment, the spray dryer is a pressure nozzle spray dryer. In such a spray-drying process, the water-containing solid phase particles are sprayed in contact with a hot gas (usually air) to vaporize the water. Drying is controlled by the temperature of the gas and the distance the particles travel in contact with the gas. This is because these parameters tend to form a dry epidermis on the partially dried particles of the solid phase and subsequently burst if the water trapped in the particles evaporates and attempts to leak. Adjusting to achieve too fast drying is generally undesirable. Similarly, it is desirable to provide the catalyst in a form with as little plugged water as possible. Therefore, if a fluid bed reactor is used and fine spherical particles are desired, it is desirable to select the conditions of spray drying to achieve complete drying without bursting of the particles. Thereafter, the dried catalyst material is heated to remove any remaining nitride. The denitrification temperature may range from 100C to 500C, preferably from 250C to 450C.

  Finally, the dried and denitrified catalyst precursor is calcined to form a finished catalyst. In one embodiment, the calcination is accomplished in air. In another embodiment, the calcination is accomplished in an inert atmosphere. In one embodiment, the catalyst precursor is calcined in nitrogen. The calcination conditions include a temperature range from about 300C to about 700C, more preferably from about 350C to about 650C, and in some embodiments, the calcination may be about 600C. In one embodiment, the calcination may be completed in multiple stages at increasing temperatures. In one embodiment, the first calcination step is performed at a temperature ranging from about 300C to about 450C, followed by a second calcination step at a temperature ranging from about 500C to about 650C. Done in

Ammoxidation processThe catalyst of the present invention comprises an olefin selected from the group consisting of propylene, isobutylene or a mixture thereof, comprising the olefin in the gas phase, at high temperature and pressure, in the presence of the catalyst, comprising molecular oxygen. It is useful in an ammoxidation process to convert to acrylonitrile, methacrylonitrile and mixtures thereof by reacting with gas and ammonia, respectively. The catalyst of the present invention is also useful for the ammoxidation of methanol to hydrogen cyanide and the ammoxidation of ethanol to acetonitrile. In one embodiment using the catalysts described herein, methanol and / or ethanol is used to increase the production of hydrogen cyanide and / or acetonitrile by-products from such processes, such as propylene, isobutylene or The mixture can be co-fed to a process for ammoxidation to acrylonitrile, methacrylonitrile or a mixture thereof.

Preferably, the ammoxidation reaction is performed in a fluidized bed reactor, although other types of reactors are envisioned, such as transport line reactors. Fluid bed reactors for the production of acrylonitrile are well known in the prior art. For example, the reactor design described in US Pat. No. 3,230,246, which is incorporated herein by reference, is suitable.
The conditions for the ammoxidation reaction to take place are evidenced by U.S. Patent Nos. 5,093,299; 4,863,891; 4,767,878 and 4,503,001. It is also well known in the prior art and is incorporated herein by reference. Typically, the ammoxidation process is performed by contacting propylene or isobutylene with a fluidized bed catalyst at elevated temperatures in the presence of ammonium and oxygen to produce acrylonitrile or methacrylonitrile. Any source of oxygen can be used. However, it is preferred to use air for economic reasons. The typical molar ratio of oxygen to olefin in the feed should be in the range 0.5: 1 to 4: 1, preferably 1: 1 to 3: 1.

  The molar ratio of ammonia to olefin in the feed during the reaction may vary between 0.5: 1 and 2: 1. Although there is no practical upper limit for the ammonia-olefin ratio, there is generally no reason to exceed the 2: 1 ratio for economic reasons. Suitable feed ratios for use with the catalyst of the present invention for the production of acrylonitrile from propylene are ammonia to propylene ratios in the range of 0.9: 1 to 1.3: 1, and 8.0: Air to propylene ratio of 1-12.0: 1. The catalysts of the present invention can provide high yields of acrylonitrile at relatively low ammonia to propylene feed ratios of about 1: 1 to about 1.05: 1. These “low ammonia conditions” help reduce unreacted ammonia in the reactor effluent, a condition known as “ammonia breakthrough” and subsequently reduce process waste. Will help you. In particular, unreacted ammonia must be removed from the reactor effluent before acrylonitrile recovery. Unreacted ammonia is typically removed by contacting the reactor effluent with sulfuric acid to obtain ammonium sulfide or contacting the reactor effluent with acrylic acid to obtain ammonium acrylate, which is In both cases, a stream of process effluent is produced and / or discarded.

The reaction is carried out at a temperature between the range of about 260C to 600C, a preferred range is 310C to 500C, and particularly preferred is 350C to 480C. The contact time is not critical, but is generally in the range of 0.1 to 50 seconds, preferably a contact time of 1 to 15 seconds.
The product of the reaction can be recovered or purified by any of the methods known to those skilled in the art. One such method involves purifying the exhaust gas from the reactor using cold water or a suitable solvent to remove the product of the reaction, and then purifying the reaction product by distillation.
A first utility of the catalysts prepared by the process of the present invention is for the ammoxidation of propylene to acrylonitrile. Other utilities include ammoxidation of propane to acrylonitrile, ammoxidation of an alcohol selected from the group consisting of methanol, ethanol or mixtures thereof to hydrogen cyanide (HCN), acetonitrile and mixtures thereof, and acrylonitrile of glycerol Including any of the ammoxidation to
The catalyst prepared by the process of the present invention may also be used for the oxidation of propylene to acrolein and / or acrylic acid. Such a process typically involves the conversion of propylene to acrolein first in a first stage in the presence of a catalyst, and the acrolein is first converted to acrolein in a second stage in the presence of a catalyst. It is a two step process that is converted to acrylic acid. The catalysts described herein are suitable for use in the first stage for the oxidation of propylene to acrolein.

Reforming HCN Production During Ammoxidation In one embodiment of the present invention, the yield of hydrogen cyanide is calculated according to the formula:
A ₂ Mo _z O _{4 + 3 (z-1)}
Wherein A is Rb, Li, Na, K, Cs or a mixture thereof;
z is from 1 to about 8) by adding to the catalyst at least one alkali molybdate compound, as compared to the amount of acrylonitrile and methacrylonitrile produced in the process. The alkali molybdate compound can be unsupported or supported on a suitable carrier such as silica, alumina, zirconia, titania or mixtures thereof. When supported, the support or carrier comprises between 1% and 99% by weight of the combination of the alkali molybdate compound and the support. The amount of the alkali molybdate compound added to the catalyst ranges from 0.01% to about 10% by weight, based on the weight of the catalyst composition.
For the catalyst systems described herein above (ie, defined by 0.4 <b / (a + h) and 0.3 ≦ (a + h) / d), the addition of the alkali molybdate is “ It is particularly beneficial to increase the level of nitrogen insertion or utilization, described above as "α", which is how effective the catalyst is at utilizing ammonia for the ammoxidation of propylene to acrylonitrile. It is a criterion of what is. The catalyst of the present invention is characterized by a high "α" (ie, greater than 102.5), which indicates how effective the catalyst is at utilizing ammonia for the ammoxidation of propylene to acrylonitrile. It is a standard.

In addition, when an alkali molybdate compound is added to the catalyst for the purpose of increasing hydrogen cyanide production, this trend can be attributed to MoO ₃ , ammonium molybdate, ammonium heptamolybdate, ammonium dimolybdate and mixtures thereof. The reversal can be effected by adding a molybdenum oxide compound selected from the group to the catalyst and the alkali molybdate mixture catalyzing the ammoxidation process. Accordingly, the addition of the molybdenum oxide compound to the catalyst and alkali molybdate mixture increases the yield of acrylonitrile and methacrylonitrile (ie, the acrylonitrile and methacrylonitrile produced) as compared to the amount of hydrogen cyanide produced in the process. And / or the amount of methacrylonitrile will increase until it approaches or returns to the level present prior to the addition of the alkali molybdate, and the amount of hydrogen cyanide will be present prior to the addition of the alkali molybdate. Will decrease until approaching or returning to a level). The molybdenum oxide compound may or may not be supported on a suitable carrier such as silica, alumina, zirconia, titania or a mixture thereof. When supported, the support or carrier comprises between 1% and 99% by weight of the combination of the molybdenum oxide compound and the support. The amount of the molybdenum oxide compound added to the catalyst ranges from 0.01% to about 10% by weight, relative to the weight of the catalyst composition.

The alkali molybdate compound and / or the molybdenum oxide compound may be added to the catalyst in situ, ie, the catalyst may be added to the catalyst to operate in the reactor or may be added to the catalyst outside the reactor. . In one embodiment, an alkali molybdate or molybdenum oxide compound is added to (ie, mixed with) a fresh fluidized bed ammoxidation catalyst, which is then maintained at the catalyst bed height in the reactor. To the reactor as a "make-up" catalyst and replace the catalyst due to loss from the reactor in waste or friction.
Specific Embodiments To illustrate the present invention, catalysts prepared according to the present invention were evaluated and compared under similar conditions to similar catalysts prepared by prior art methods outside the scope of the present invention. These examples are provided for illustrative purposes only. The catalyst composition for each example is as indicated after the example number. The example designated by “C” is a comparative example.

(Comparative Example C1)
Ni ₄ Mg ₃ Fe _0.9 Rb _0.2 Cr _0.05 Bi _1.25 Ce _1.25 Mo _12.85 Ox + 50% by mass 38.2 nm SiO ₂
Reaction mixture A was heated by heating 1370.303 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (1245.730 g) with stirring over 30 minutes to form a clear, colorless solution. Prepared.
Deionized water 257.123ml heated to 55 ° C., then stirring _{Fe (NO 3) 3 · 9H} 2 O (285.052g), Ni (NO 3) 2 · 6H 2 O (911.870g), Reaction mixture B was prepared by adding Mg (NO ₃ ) ₂ .6H ₂ O (603.024 g) and Cr (NO ₃ ) ₃ .9H ₂ O (15.685 g).
Reaction mixture C was heated by heating a relative amount of 586.185 ml of deionized water to 65 ° C. and then stirring for 30 minutes while adding ammonium heptamolybdate (532.896 g) to form a clear, colorless solution. Was prepared.

(I) heating 1074.497 g of a 50% by weight aqueous solution of (NH ₄ ) ₂ Ce (NO ₃ ) ₆ to 55 ° C., (ii) while the solution is being stirred and heated, Bi (NO ₃ ) the ₃ · 5H ₂ O _(475.357g) and RbNO ₃ (23.121g) be added sequentially and the reaction mixture D was prepared.
Reaction mixture E was prepared by adding silica sol (5487.8 g, 41 wt% silica) to reaction mixture A followed by reaction mixture B with stirring.
Reaction mixture C was added to reaction mixture D to prepare reaction mixture F by causing precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes, while the temperature was maintained in the 50-55 ° C range.
Thereafter, reaction mixture F was added to reaction mixture E to form the final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. Thereafter, the slurry was spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment in air at 290 ° C. for 3 hours followed by a further 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Comparative Example C2)
Ni ₆ Mg ₁ Fe _0.7 Rb _0.1 Cr _0.05 Bi _0.83 Ce _1.67 Mo _12.85 O _x + 50% by mass 38.2 nm SiO ₂
Reaction mixture A was heated by heating 304.303 ml of deionized water to 65 ° C. and then stirring for 30 minutes while adding ammonium heptamolybdate (276.639 g) to form a clear, colorless solution. Prepared.
Deionized water 38.310ml heated to 55 ° C., with subsequent _{stirring, Fe (NO 3) 3 ·} 9H 2 O (48.962g), Ni (NO 3) 2 · 6H 2 O (302.070g) , Mg (NO ₃ ) ₂ .6H ₂ O (44.391 g) and Cr (NO ₃ ) ₃ . Reaction mixture B was prepared by adding 9H ₂ O (11.547 g).
Prepare reaction mixture C by heating 127.774 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (116.158 g) with stirring over 30 minutes to form a clear, colorless solution. did.

(I) heating 317.026 g of a 50% by weight aqueous solution of (NH ₄ ) ₂ Ce (NO ₃ ) ₆ to 55 ° C .; (ii) stirring and heating the solution while continuously adding Bi (NO ₃ ) by the addition of ₃ · 5H ₂ O _(69.706g) and RbNO ₃ (8.510g), and the reaction mixture D was prepared.
Reaction mixture E was prepared by adding silica sol (1219.5 g, 41% by weight silica) to reaction mixture A followed by addition of reaction mixture B with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes, while the temperature was maintained in the range of 50-55 ° C.
Thereafter, reaction mixture F was added to reaction mixture E to form a final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The slurry was then spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment in air at 290 ° C. for 3 hours followed by a further 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Examples 1 and 2)
Ni ₄ Mg ₃ Fe _1.2 Rb _0.2 Cr _0.05 Bi _1.25 Ce _1.25 Mo _12.85 O _x + 50% by mass 38.2 nm SiO ₂
The reaction mixture A was heated by heating 1355.861 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (1235.419 g) with stirring for 30 minutes to form a clear, colorless solution. deionized water prepared 265.465ml heated to 55 ° C., _{then, Fe (NO 3) 3 ·} 9H 2 O (376.923g), Ni (NO 3) 2 · 6H 2 O (904.322g), by adding with stirring _{mg (NO 3) 2 · 6H} 2 O (598.033g) and _{Cr (NO 3) 3 · 9H} 2 O (15.555g), and the reaction mixture B was prepared.
Reaction mixture C was heated by heating 581.333 ml of deionized water to 65 ° C. and then stirring for 30 minutes while adding ammonium heptamolybdate (528.485 g) to form a clear, colorless solution. Prepared.

(I) heating 106.5.603 g of a 50% by weight (NH ₄ ) ₂ Ce (NO ₃ ) ₆ aqueous solution to 55 ° C .; (ii) stirring and heating the solution while Bi (NO ₃ ) ₃ .5H ₂ Reaction mixture D was prepared by the sequential addition of O (471.422 g) and RbNO ₃ (22.930 g).
Reaction mixture E was prepared by adding silica sol (5487.8 g, 41% by weight silica) to reaction mixture A followed by reaction mixture B with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, causing precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes, while the temperature was maintained in the 50-55 ° C range.
Thereafter, reaction mixture F was added to reaction mixture E to form a final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The slurry was then spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The obtained powder was heat-treated at 290 ° C. in air for 3 hours, and then denitrified by heating at 425 ° C. for another 3 hours. The powder was then calcined at 560 ° C. in air for 3 hours.

(Examples 3 and 4)
Ni ₆ Mg ₁ Fe ₁ Rb _0.2 Cr _0.05 Bi ₁ Ce _1.22 Mo _12.505 O _x + 50% by mass 38.2 nm SiO ₂
The reaction mixture A was prepared by heating 1399.413 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (1272.194 g) with stirring for 30 minutes to form a clear, colorless solution. Prepared.
259.349 ml of deionized water was heated to 55 ° C. and then, with stirring, Fe (NO ₃ ) ₃ .9H ₂ O (320.780 g), Ni (NO ₃ ) ₂ .6H ₂ O (1385.318 g), by adding _{mg (NO 3) 2 · 6H} 2 O (203.582g) and _{Cr (NO 3) 3 · 9H} 2 O (15.886g), and the reaction mixture B was prepared.
The reaction mixture C was prepared by heating 528.924 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (480.840 g) with stirring for 30 minutes to form a clear, colorless solution. (I) heating 1062.136 g of a 50% by weight aqueous solution of (NH ₄ ) ₂ Ce (NO ₃ ) ₆ to 55 ° C .; (ii) continuously stirring and heating the solution, NO ₃₎ by adding ₃ · 5H ₂ O _(385.155g) and RbNO ₃ (23.417g), and the reaction mixture D was prepared.

Reaction mixture E was prepared by adding silica sol (5263.2 g, 41 wt% silica) to reaction mixture A followed by reaction mixture B with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, causing precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes while maintaining the temperature in the 50-55 ° C range.
Thereafter, reaction mixture F was added to reaction mixture E to form the final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while cooling to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. Thereafter, the slurry was spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment at 290 ° C. in air for 3 hours followed by a further 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Example 5)
Ni ₄ Mg ₃ Fe _1.2 Rb _0.2 Cr _0.05 Bi _1.25 Ce _1.25 Mo _12.730 O _x +50 wt 38.2 nm SiO ₂
The reaction mixture A was heated by heating 150.66 ml of deionized water to 65 ° C. and then adding, with stirring, for 30 minutes, ammonium heptamolybdate (136.60 g) to form a clear, colorless solution. Prepared.
29.93 ml of deionized water was heated to 55 ° C. and then, with stirring, Fe (NO ₃ ) ₃ .9H ₂ O (42.2625 g), Ni (NO ₃ ) ₂ .6H ₂ O (101.42 g) ), Mg (NO ₃ ) ₂ .6H ₂ O (67.0604 g) and Cr (NO ₃ ) ₃ .9H ₂ O (1.7441 g) to prepare a reaction mixture B.
The reaction mixture C was heated by heating 71.75 ml of deionized water to 65 ° C. and then stirring with addition of ammonium heptamolybdate (59.3332 g) for 30 minutes to form a clear, colorless solution. Prepared.
(I) heating 119.53 g of a 50% by weight aqueous solution of (NH ₄ ) ₂ Ce (NO ₃ ) ₆ to 55 ° C .; (ii) continuously stirring and heating the solution to Bi (NO ₃ ) ₃ Reaction mixture D was prepared by adding 5H ₂ O (52.8606 g) and RbNO ₃ (2.7027 g).
Reaction mixture E was prepared by adding silica sol (609.76 g, 41 wt% silica) to reaction mixture A followed by reaction mixture B with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, causing precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes while maintaining the temperature in the range of 50-55 ° C.
Thereafter, reaction mixture F was added to reaction mixture E to form a final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. Thereafter, the slurry was spray-dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment in air at 290 ° C. for 3 hours, followed by another 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Example 6)
Ni ₄ Mg ₃ Fe _1.2 Rb _0.2 Cr _0.05 Bi _1.25 Ce _1.25 Mo _12.130 O _x + 50% by mass 38.2 nm SiO ₂
Reaction mixture A was prepared by heating 144.67 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (131.32 g) with stirring for 30 minutes to form a clear, colorless solution. Prepared.
30.87 ml of deionized water is heated to 55 ° C. and then, with stirring, Fe (NO ₃ ) ₃ .9H ₂ O (43.5883 g), Ni (NO ₃ ) ₂ .6H ₂ O (104.57 g) , Mg (NO ₃ ) ₂ .6H ₂ O (69.1397 g) and Cr (NO ₃ ) ₃ . Reaction mixture B was prepared by adding 9H ₂ O (1.7983 g).
The reaction mixture C was prepared by heating 74.12 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (61.1793 g) with stirring for 30 minutes to form a clear, colorless solution. Prepared.

(I) 123.30g of 50 _{wt% (NH 4) 2 Ce (} NO 3) 6 solution that is heated to 55 ° C., (ii) solution, while stirring and heating, continuously Bi (NO ₃ ) by the addition of ₃ · 5H ₂ O _(54.5021g) and RbNO ₃ (2.7847g), the reaction mixture D was prepared.
Reaction mixture E was prepared by adding silica sol (609.80 g, 41% by weight silica) to reaction mixture A, followed by addition of reaction mixture B, with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, causing precipitation of an orange solid (the resulting mixture was a precipitate slurry). Stirring of the precipitate slurry was continued for 15 minutes while maintaining the temperature in the 50-55 ° C range.
Thereafter, reaction mixture F was added to reaction mixture E to form a final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. The slurry was then spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment at 290 ° C. in air for 3 hours followed by a further 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Example 7)
Ni4Mg3Fe1.2Rb0.192Cr0.05Bi1.0Sm0.1Ce1.5Mo12.996Ox + 50% by mass 38.2 nm SiO2
The reaction mixture A was heated by heating 152.49 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (139.06 g) with stirring for 30 minutes to form a clear, colorless solution. Prepared.
28.35 ml of deionized water is heated to 55 ° C. and then, with stirring, Fe (NO ₃ ) ₃ .9H ₂ O (41.7329 g), Ni (NO ₃ ) ₂ .6H ₂ O (100.16 g) , Mg (NO ₃ ) ₂ .6H ₂ O (66.2090 g) and Cr (NO ₃ ) ₃ . By adding 9H ₂ O (1.7272g), and the reaction mixture B was prepared.
The reaction mixture C was heated by heating 70.69 ml of deionized water to 65 ° C. and then adding ammonium heptamolybdate (58.4395 g) with stirring for 30 minutes to form a clear, colorless solution. Prepared.

(I) heating 141.57 g of a 50% by weight aqueous solution of (NH ₄ ) ₂ Ce (NO ₃ ) ₆ to 55 ° C., (ii) stirring and heating the solution while continuously adding Bi ( _{NO 3) 3 · 5H 2 O} (41.7512g), by adding RbNO ₃ (2.4389g) and _{Sm (NO 3) 3 · 6H} 2 O (3.8270g), the reaction mixture D was prepared.
Reaction mixture E was prepared by adding silica sol (609.76 g, 41% by weight silica) to reaction mixture A, followed by addition of reaction mixture B, with stirring.
Reaction mixture F was prepared by adding reaction mixture C to reaction mixture D, which resulted in the precipitation of an orange solid (the resulting mixture was a precipitate slurry). The temperature of the precipitate slurry was maintained in the 50-55 ° C. range while stirring was continued for 15 minutes.
Thereafter, reaction mixture F was added to reaction mixture E to form a final catalyst precursor slurry.
The catalyst precursor slurry was allowed to stir for 1 hour while it was cooled to approximately 40 ° C. It was then homogenized in a blender for 3 minutes at 5000 rpm. Thereafter, the slurry was spray dried in a spray dryer at an inlet / outlet temperature of 325/140 ° C. The resulting powder was denitrified by heat treatment at 290 ° C. in air for 3 hours followed by a further 3 hours at 425 ° C. Thereafter, the powder was calcined at 560 ° C. for 3 hours in air.

(Example 8)
The catalyst of the example was prepared using the same preparation as in example 7, except that 0.094 grams of K ₂ MoO ₄ solid crystals were added to the finished catalyst.
Example 9
This example was a continuation of the catalyst test of Example 8. After 382 hours in the stream, 0.144 grams of MoO3 was added to the Example 8 catalyst and the test for ammoxidation of propylene to acrylonitrile was continued.

Catalyst Testing All catalysts were tested in a bench scale reactor for the ammoxidation of propylene to acrylonitrile using 30 g of catalyst. All tests were performed in a 40 cc fluid bed reactor. Propylene was fed into the reactor at the rates shown in Tables 1 and 3, between 0.080 and 0.100 WWH (i.e., weight of propylene / weight of catalyst / hour). The pressure inside the reactor was maintained at 10 psig. The reaction temperature was 430 ° C. A sample of the reaction product was collected several days after the test (between about 140 to about 190 hours in the stream). The reactor effluent was collected with a bubble scrubber containing a cold HCl solution. The off-gas rate was measured with a soap film meter and the off-gas composition was determined at the end of the operation with the aid of a gas column chromatography equipped with a split column gas analyzer. At the end of the recovery operation, the entire scrubber solution was diluted to approximately 200 grams with dilution water. A weighed amount of 2-butanone was used as an internal standard in approximately 50 gram aliquots of the diluted solution. Two μl samples were analyzed on a GC equipped with a flame ionization detector and a Carbowax ™ column. The amount of NH _3, was determined by titrating the free HCl excess with NaOH solution. The propylene conversion and acrylonitrile yield for the catalysts tested are as shown in Tables 1 and 3. After addition of caustic iodide, HCN was analyzed by titration with an AgNO3 solution.

Notes on Tables 1, 2 and 3 (when available):
1. “WWH” is the mass of propylene per hour per mass of catalyst being fed. “T ° C.” is the reactor temperature in Celsius. "HOS" is the time in the stream.
4. “% C ₃ ”, “Conv” or “% PC” is the propylene conversion (ie, the mole percent per pass conversion of propylene to all products).
5. "% AN yield" is the percent acrylonitrile yield.
6). "% AN yield" is the percent acrylonitrile yield.
7). “% Acetoyield” is the acetonitrile yield “Α” is calculated as follows: α = [(% AN + (3 ×% HCN) + (1.5 ×% ACN)) ÷% PC] × 100
9. "B / (a + h) is the ratio of atoms of iron to atoms of bismuth plus cerium atoms in the composition.
10. "(A + h) / d" is the ratio of bismuth atoms plus cerium atoms to atoms of the D element (ie, nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium) in the composition. It is.
11. For catalysts suitable for the formulas described herein, "m-[(3a + 2b + c + 2d + 3h + 3n) / 2]" is the number of molybdenum atoms (subscript "m" from the formula) divided by two. [(3 x number of bismuth atoms 0 + (2 x number of iron atoms) + (number of lithium, sodium, potassium, rubidium and cesium atoms) + (2 x nickel, cobalt, manganese, zinc, magnesium) , Calcium, strontium, cadmium, and barium) + (3 × the number of cerium atoms) + (3 × the number of chromium atoms)].

The present invention is directed to improved and new mixed metal oxide catalysts for the ammoxidation of propylene and / or isobutylene. This improved catalyst provides a large overall conversion of propylene and / or isobutylene to hydrogen cyanide while maintaining acrylonitrile and / or methacrylonitrile production levels at substantially the same level as prior art catalysts.
The data in Tables 1 and 2 clearly demonstrate the benefits of the present invention. Examples 1 to 6 have “b / (a + h)” and “(a + h) / d” values within the claimed invention (ie, 0.4 <b / (a + h) and 0.3 ≦). (A + h) / d is a larger hydrogen cyanide yield (approximately 1 to 1) than that of C1 to C2 catalysts outside one or both of the claimed "b / (a + h)" and "(a + h) / d" ranges. 3% higher).

  The data in Table 3 clearly demonstrates one embodiment of the present invention. In particular, when the catalyst of the present invention (ie, the composition of Example 7) is combined with an alkali molybdate, the propylene to acrylonitrile using hydrogen cyanide formed as a by-product (ie, the mixture of Example 8). For ammoxidation of, there will be a further increase in HCN yield and a further increase in nitrogen efficiency, as indicated by an increase in the α-factor. As shown in Example 9, this effect can be reversed. Example 9 demonstrates that the catalyst mixture of Example 8 can be returned to a state that provides a high yield of acrylonitrile by the addition of molybdenum oxide (ie, in Example 9, the catalyst is exemplified as Example 7). (Return to the performance of the base composition).

  While the foregoing description and the above embodiments are typical for the practice of the present invention, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of this description. Accordingly, all such alternatives, modifications and variations are intended to be encompassed and within the concept and broad scope of the appended claims.

Claims (36)

A catalyst composition comprising a composite of a metal oxide,
The relative ratios of the listed elements in the catalyst composition are represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Cr n Q q O x
Wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium;
D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium;
E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium At least one element selected from the group consisting of:
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one of samarium, praseodymium and neodymium;
a, b, c, d, e, f, g, h, n, m, and x are bismuth (Bi), iron (Fe), A, and “m” atoms of molybdenum (Mo), respectively. The atomic ratio of D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O);
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is 0-5,
d is 0.1 to 12,
e is 0-5,
f is 0-5,
g is 0 to 0.2,
h is 0.01 to 5,
m is 10 to 15,
n is 0-5,
q is 0 to 2.476;
x is the number of oxygen atoms required to satisfy the valency requirements of the other constituent elements present;
A catalyst composition represented by 0.4 <b / (a + h) and 0.3 ≦ (a + h) / d).   The catalyst composition according to claim 1, wherein 0 ≦ m− (3a + 2b + c + 2d + 3h + 3n) /2≦1.0.   The catalyst composition according to claim 1, wherein 0.3 ≦ (a + h) / d ≦ 1.   The catalyst composition according to claim 1, wherein 0.45≤ (a + h) / d≤1.   The catalyst composition according to claim 1, wherein 0.8 ≦ h / b ≦ 5.   The catalyst composition according to claim 1, wherein 0.5 ≦ a / h <1.5.   The catalyst composition according to claim 1, wherein 0 ≦ q / (a + h + q) and q / (a + h + q) <0.16.   The catalyst composition according to claim 1, wherein D is nickel. formula:
A ₂ Mo _z O _{4 + 3 (z-1)}
Wherein A is Rb, Li, Na, K, Cs or a mixture thereof;
z is from 1 to about 8)
The catalyst composition according to claim 1, further comprising at least one alkali molybdate compound represented by   A support comprising a support selected from the group consisting of silica, alumina, zirconia, titania or mixtures thereof, wherein the support comprises between 1% and 99% by weight of a combination of molybdate and a support. 10. The alkali molybdate compound according to 9.   10. The catalyst composition of claim 9, comprising between 0.01% and about 10% by weight of the alkali molybdate compound, based on the total weight of the catalyst composition. When using the catalyst composition as a catalyst for the production of acrylonitrile, acetonitrile and hydrogen cyanide in a process comprising contacting propylene, ammonia and oxygen in the gas phase in the presence of a catalyst at an elevated temperature, the acrylonitrile from said process , Acetonitrile and hydrogen cyanide have the following relative yields:
α = [(% AN + (3 ×% HCN) + (1.5 ×% ACN)) ÷% PC] × 100
Wherein% AN is the acrylonitrile yield and% AN ≧ 82;
% HCN is hydrogen cyanide yield and% HCN ≧ 5 and% ACN is acetonitrile yield;
% PC is the propylene conversion,
α is greater than 102.5)
The catalyst composition according to claim 1, defined by: By-products are formed by reacting an olefin selected from the group consisting of propylene, isobutylene and mixtures thereof with a gas containing molecular oxygen and ammonia in the gas phase at high temperatures and pressures in the presence of a catalyst. A process for converting acrylonitrile, methacrylonitrile and mixtures thereof with hydrogen cyanide produced as a product, wherein the relative ratio of the listed elements in the catalyst is represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Cr n Q q O x
Wherein A is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium and cesium;
D is at least one element selected from the group consisting of nickel, cobalt, manganese, zinc, magnesium, calcium, strontium, cadmium and barium;
E is at least one element selected from the group consisting of tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, lead and germanium At least one element selected from the group consisting of:
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one of samarium, praseodymium and neodymium;
a, b, c, d, e, f, g, h, n, m, and x are bismuth (Bi), iron (Fe), A, and “m” atoms of molybdenum (Mo), respectively. The atomic ratio of D, E, F, G, cerium (Ce), chromium (Cr), molybdenum (Mo) and oxygen (O);
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is from 0 to 5,
d is 0.1 to 12,
e is 0-5,
f is 0 to 5,
g is 0 to 0.2;
h is 0.01 to 5,
m is 10 to 15,
n is 0 to 5,
q is 0 to 2.476;
x is the number of oxygen atoms required to satisfy the valency requirements of the other constituent elements present;
0.4 <b / (a + h) and 0.3 ≦ (a + h) / d)
The method, represented by The yield of hydrogen cyanide has the formula:
A ₂ Mo _z O _{4 + 3 (z-1)}
Wherein A is Rb, Li, Na, K, Cs or a mixture thereof;
z is from 1 to about 8)
14. The method of claim 13, wherein the addition of at least one alkali molybdate compound represented by the formula to the catalyst increases the amount of acrylonitrile and methacrylonitrile produced in the process.   14. The method of claim 13, wherein the catalyst composition comprises between 0.01% and about 10% by weight of the alkali molybdate compound, based on the total weight of the catalyst composition. The yield of acrylonitrile and methacrylonitrile, MoO _3, ammonium molybdate, ammonium heptamolybdate, by addition to the catalyst of molybdenum oxide compound selected from the group consisting of ammonium dimolybdate, and mixtures thereof, produced in the process 14. The method of claim 13, wherein the amount is increased as compared to the amount of hydrogen cyanide performed.   17. The method of claim 16, wherein the amount of the molybdenum oxide compound added to the catalyst ranges from 0.01% to about 10% by weight based on the weight of the catalyst.   14. The method according to claim 13, wherein 0 <m- (3a + 2b + c + 2d + 3h + 3n) / 2 <1.0 in the catalyst.   14. The method according to claim 13, wherein 0.3 ≦ (a + h) / d ≦ 1 in the catalyst.   14. The method of claim 13, wherein 0.45 <(a + h) / d <1 in the catalyst.   14. The method according to claim 13, wherein 0.8≤h / b≤5 in the catalyst.   14. The method according to claim 13, wherein 0.5? A / h <1.5 in the catalyst.   14. The method according to claim 13, wherein in the catalyst 0 <q / (a + h + q) and q / (a + h + q) <0.16.   14. The method according to claim 13, wherein D is nickel in the catalyst. Less than:
α = [(% AN + (3 ×% HCN) + (1.5 ×% ACN)) ÷% PC] × 100
Wherein% AN is the acrylonitrile yield and% AN ≧ 82;
% HCN is hydrogen cyanide yield and% HCN ≧ 5;
% ACN is the acetonitrile yield,
% PC is the propylene conversion,
α is greater than 102.5)
14. The method of claim 13, wherein the method is defined by: A catalyst composition comprising a metal oxide composite, wherein the relative ratio of the listed elements in the catalyst is represented by the following formula:
_{Mo m Bi a Fe b A c} D d E e F f G g Ce h Ni i Co j Mn k Mg l Q q O x
Wherein A is at least one element selected from the group consisting of sodium, potassium, rubidium and cesium;
D is at least one element selected from the group consisting of zinc, calcium, strontium, cadmium and barium;
E is at least one element selected from the group consisting of chromium, tungsten, boron, aluminum, gallium, indium, phosphorus, arsenic, antimony, vanadium and tellurium;
F is lanthanum, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, aluminum, gallium, indium, thallium, silicon, germanium and about At least one element selected from the group consisting of less than 10 ppm lead;
G is at least one element selected from the group consisting of silver, gold, ruthenium, rhodium, palladium, osmium, iridium, platinum and mercury;
Q is at least one of samarium, praseodymium and neodymium;
Here, a is 0.05 to 7,
b is 0.1 to 7,
c is 0.01 to 5,
d is 0 to 12,
e is 0-5,
f is 0 to 5,
g is 0 to 0.2;
h is 0.01 to 5,
i is 0.1 to 12,
j is 0 to 12,
k is 0 to 12,
l is from 0 to 12,
m is 10 to 15; q is 0 to 2.476;
x is the number of oxygen atoms required to satisfy the valency requirements of the other constituent elements present;
0.4 <b / (a + h),
A catalyst composition represented by 0.2 <i / (i + j + k + 1), and z = d + i + j + k + 1 and 0.3 ≦ (a + h) / z.   The catalyst composition according to claim 26, wherein 0 ≦ m− (3a + 2b + c + 2d + 3h + 3n) /2≦1.0.   The catalyst composition according to claim 26, wherein 0.3 ≦ (a + h) / d ≦ 1.   The catalyst composition according to claim 26, wherein 0.45 ≦ (a + h) / d ≦ 1.   The catalyst composition according to claim 26, wherein 0.8 ≦ h / b ≦ 5.   The catalyst composition according to claim 26, wherein 0.5 ≦ a / h <1.5.   The catalyst composition according to claim 26, wherein 0 ≦ q / (a + h + q) and q / (a + h + q) <0.16. formula:
A ₂ Mo _z O _{4 + 3 (z-1)}
Wherein A is Rb, Li, Na, K, Cs or a mixture thereof;
27. The catalyst composition of claim 26, further comprising at least one alkali molybdate compound represented by z is from 1 to about 8).   The alkali molybdate compound comprises a support selected from the group consisting of silica, alumina, zirconia, titania or mixtures thereof, wherein the support comprises between 1% and 99% by weight of the alkali molybdate and the support. 34. The catalyst composition of claim 33, comprising a body combination.   34. The catalyst composition of claim 33, comprising between 0.01% and about 10% by weight of the alkali molybdate compound, based on the total weight of the catalyst composition. When using the catalyst composition as a catalyst for the production of acrylonitrile, acetonitrile and hydrogen cyanide in a process comprising contacting propylene, ammonia and oxygen in the gas phase in the presence of a catalyst at an elevated temperature, the acrylonitrile from said process , Acetonitrile and hydrogen cyanide have the following relative yields:
α = [(% AN + (3 ×% HCN) + (1.5 ×% ACN)) ÷% PC] × 100
Wherein% AN is the acrylonitrile yield and% AN ≧ 82;
% HCN is hydrogen cyanide yield and% HCN ≧ 5;
% ACN is the acetonitrile yield,
% PC is the propylene conversion,
α is greater than 102.5)
27. The catalyst composition according to claim 26, defined by: